CDC IDs Trends in Pediatric Flu Deaths With Influenza-Linked Encephalopathy

MONDAY, March 3, 2025 (HealthDay News) — During the 2010-2011 to 2024-2025 influenza seasons, 9 percent of pediatric influenza-associated deaths had influenza-associated encephalopathy or encephalitis (IAE), according to research published in the Feb. 27 issue of the U.S. Centers for Disease Control and Prevention Morbidity and Mortality Weekly Report.

Noting that reports were received of children with influenza-associated acute necrotizing encephalopathy (ANE), a severe form of IAE, in late January 2025, Amara Fazal, M.D., from the CDC in Atlanta, and colleagues examined trends in the proportions of cases with IAE among influenza-associated pediatric deaths reported during the 2010-2011 through 2024-2025 influenza seasons.

The researchers found 9 percent of the 1,840 pediatric influenza-associated deaths during the 2010-2011 to 2024-2025 seasons had IAE, ranging from 0 percent in the 2020-2021 season to 14 percent in the 2011-2012 season; nine of 68 (13 percent) had IAE based on preliminary data for the 2024 to 2025 season. The median age of patients with fatal IAE was 6 years across seasons; most (54 percent) had no underlying conditions and 20 percent had received influenza vaccination. It is unknown whether the numbers of cases this season vary from expected numbers because there is no dedicated national surveillance for IAE or ANE.

“Use of standardized criteria by health care providers for IAE case identification and establishment of a mechanism for public health reporting will improve understanding of the incidence and impact of this serious influenza complication,” the authors write.

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